Abstract

International intercomparisons of models to assess the impact of ionising radiation on wildlife have
identified radionuclide transfer assumptions as a significant source of uncertainty in the modelling process.
There is a need to improve the underpinning data sets on radionuclide transfer to reduce this uncertainty,
especially for poorly-studied ecosystems such as coastal sand dunes. This paper presents the results of the
first published study of radionuclide transfer to invertebrates and small mammals in a coastal sand dune
ecosystem. Activity concentrations of 137Cs, 238Pu, 239+240Pu and 241Am are reported for detritivorous,
herbivorous, carnivorous and omnivorous biota. Differences in activity concentrations measured in the sand
dune biota are related to the trophic level of the organisms and the influence of sea-to-land transfer is
apparent in the food chain transfer observed at the site. There are notable differences in the concentration
ratios (CRs) calculated for the sand dune biota compared to other terrestrial ecosystems, especially for the
small mammals which have CRs that are two orders of magnitude lower than the generic terrestrial
ecosystem CRs published by the recent EC EURATOM ERICA project. The lower CRs at the sand dunes may be
due to the influence of other cations from the marine environment (e.g. K and Na) on the net radionuclide
transfer observed, but further research is required to test this hypothesis.